I also live in a sprawling western city (over 600 square miles of area), and my state has a bunch of little towns that have dried up. My job has me driving to all parts of the state, and I frequently drive through little towns that have maybe 100 people and are clustered around a grain elevator. I'm sure that affects my vision of how the Battletech universe is supposed to work.
If a planet has good resources in one location (a source of fresh water, arable farmland, access to a protected harbor) then that probably becomes your primary landing spot. You'd be cherry picking the best location on the planet. In North America (what I'm most familiar with), you've got candidates in New York City (amazing natural harbor, great river, lots of timber, but sucky weather), Seattle (great weather, great harbor, great farmland nearby, but no big rivers), San Francisco (great harbor, amazing farmland, a small river going into the mountains), and New Orleans (the bestest river ever, good harbor, access to tons of farmland up the river, but yucky swamp land). Those are the ones that stick out from a quick glance at Google Maps zoomed way out.
You'd probably send down some scientific teams to scout out each location before picking "the best" one. Going back to our North America example, I think you almost have to pick New Orleans -- the river is just that big of an advantage. You can follow it all the way up to the Great Lakes (and it connects to the Ohio River and the Illinois River and the Allegheny River), and from there it's not that far to one of your other top choices, New York City. Since there's no Panama Canal, it makes sense to concentrate your development on the side of the continent with the best natural waterways. Now you've got your primary development spot (New Orleans), your second major development spot (NYC), and tertiary development points (St Louis, Chicago, Cleveland -- all places that just "happen" to be along these major rivers that all connect together, which of course is why we built those cities in the first place). This is the sort of thing you could look at from space and get a really good idea of what places to cherry-pick.
So your dropships land and you set up your initial colony. If you did your work right, you've got a plan for your colony to be self-sufficient. On a hell world, maybe the plan is just "mine the valuable stuff and stay in the hab-domes". But on a more survivable world, you've probably got a set number of people who went to the planet with the knowledge that they were going to sail upriver and grow corn or something. You will naturally need to expand, at least to be more self-sufficient. Sticking with our Eastern United States example, the Great Lakes area gives you coal, iron, and other metals. Nearby Texas gives you oil and natural gas. You'd want to set up small settlements pretty fast to both claim them (you don't want another colony group to land on your planet and take valuable stuff), and to start providing you with needed resources. There would be a balance between places that have the most/best stuff, and what is easiest to access. It kinda depends on what your population is. As your planet grows, this might mean you abandon towns that were founded out of convenience rather than for their long-term potential.
Of course, an Earth-like planet will probably draw a lot more people than Tatooine would.